Fluid jet cutting system can be used to cut flat planar workpieces, wherein the fluid jet cutting head of the system is moved over the workpiece. The motion and inclination may be varied for reaching a desired quality of the cut surface. In some known prior art systems the cutting speed is predetermined as a set-point value, indicating the target value of an essential variable of several parameters, wherein the fluid jet cutting head is automatically controlled by the control unit from said predetermined cutting speed. The set-point value of the cutting speed is used for cutting the workpiece with regard to an optimal quality of the cut surface.
However, it has been evident for quite some time that variation in tolerances and used individual water jet cutting machines will imply that the quality of the cut surface may vary despite the predicted feature of determining the cutting speed strictly in advance. This may also be caused by variance in distance between the singular fluid jet cutting head and the workpiece, different quality of eventually used abrasive particles, different individual water pressure, small difference in material quality of the specific workpiece etc. which will produce the actual machined inclination angle or taper.
Current fluid jet cutting systems may also involve drawbacks in that they do not include any optimized control unit and data medium storing program adapted for providing the motion of the fluid jet cutting head corresponding to optimum taper and trail back inclination of the fluid jet cutting head.